Trump's previous record for most tweets in 24 hours was set on December 13, 2019, as the House Judiciary Committee held a marathon 14-hour debate on two articles of impeachment. On that day, Trump posted 123 tweets.

And, for your information, we have a record as of 4:25 pm on @realDonaldTrump. The most tweets of his presidency at 125 and counting. The most retweets ever at 110 and counting. Closing on the all time record set in 2015... pic.twitter.com/V9hLmN2lEu

As with his previous record, most of Trump's postings on Wednesday were re-tweets of Republican members of Congress, staff on his re-election campaign, and Fox News hosts defending him and seeking to discredit the Democrats' impeachment case.

He occasionally commented on the day's events himself, calling a Democratic presidential candidate "a loser" and emphasising in all-caps that he does not believe he improperly pressured Ukranian President Volodymyr Zelensky to open an investigation into his political rivals.

The historic Senate trial weighing whether to remove Trump from office began last week when Supreme Court Chief Justice John Roberts swore in the Senators who will serve as jurors.

On Tuesday, the seven House representatives designated to argue the case for convicting case and Trump's defense counsel team, led by White House counsel Pat Cipollone and attorney Jay Sekulow, debated the trial's rules.

According to those rules, both the impeachment managers and Trump's defense counsel will have 24 hours each to make their opening arguments, which will be spread over several days.

The arguments will be followed by 16-hour period when Senators can ask written questions of both sides, and then the Senate will vote on whether to subpoena additional documents and witnesses.